Analysis of Electromagnetic Characteristics of a Grounded Slab and a Parallel‐Plate Structure Using the SDDI Technique

In this paper, the electromagnetic characteristics of a grounded slab and a parallel‐plate structure are analyzed by the Spline‐type Divided‐Difference Interpolation (SDDI) technique. The technique efficiently evaluates the MoM impedance matrix elements of the multifold spectral or spatial domain integrals or summation in integrodifferential equations. The numerical results of the proposed method agree well with those of the corresponding literatures.     

A stacked array antenna able to make a very large gain and tilt the end‐fire beam at the ISM‐band

In this article, an antenna is designed to generate an end‐fire radiated beam of a very large gain for a Printed Circuit Board (PCB) structure and steer the beam at an Industrial Scientific Medical (ISM)‐band. A flush‐mounted slot‐coupled feed and two parasitic layers can increase the antenna gain substantially. This single element is made to be a 1‐by‐8 array to generate a very high gain to deliver wireless power more than single element to the far‐field zone and spot the receiver of interest without interference toward others on the azimuth plane. Furthermore, four layers of this array are stacked to tilt the beam up and down on the elevation plane for target selectivity of a higher degree and more wireless‐power transfer. The antenna system is implemented with the substrate of Rogers 4350B and operated at 2.4 GHz as the ISM‐band service, and the validity of the proposed design is verified by electromagnetic numerical simulation and physical realization. The simulation and measurement of the fabricated 1D array antenna show nearly 19 and 16 dBi, respectively as high gains. The stacked structure as a 2D array generate the titled beam moving from ?35° to 35° with the antenna gain from 17 to 20 dBi for a varying angle.     

Ground-state properties of two-dimensional quantum fluid helium: Variational hypernetted chain methods

We calculate the ground-state energies and the radial distribution functions of two-dimensional quantum fluid⁴He, mass 3 boson³He and³He within a hypernetted chain and a Fermi hypernetted chain summation method. To get more accurate results, we include three-body correlation functions in the trial wavefunctions and consider the contributions arising from elementary diagrams via scaling approximations. The two-dimensional⁴He system has a binding energy of 0.84 K at an equilibrium density 0.042 Å^?2, which is closer to the result of a Green's function Monte Carlo calculation than previous ones, while mass 3 boson³He has 0.286 K at 0.025 Å^?2. The³He system is not self-bound and therefore not a liquid state due to its statistics and light mass of the³He atom. We calculate the ground-state energy of two-dimensional liquid⁴He through a Lennard-Jones potential and that of Aziz to compare the results of both. Aziz's potential gives lower and more accurate energies than the Lennard-Jones potential, as in three dimensions.     

Graphene‐Conducting Polymer Hybrid Transparent Electrodes for Efficient Organic Optoelectronic Devices

To achieve the broad utilization of the full functionality of graphene (GR) in devices, a transfer method should be developed that can simplify the process without leaving residue of the insulating supporting layer on the surface of GR. Furthermore, stable GR doping without the use of an insulating polymer is required. Here, a new GR transfer method that uses a popular conducting polymer, poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), is reported as a new supporting layer for the transfer of GR films that are synthesized by chemical vapor deposition. The GR/PEDOT:PSS bilayer can be directly utilized without the removal process. Therefore, this transfer method simplifies the transfer process and solves the residue problem of conventional transfer methods. The stable doping of GR films is simultaneously achieved by using the PEDOT:PSS layer. The new GR/PEDOT:PSS hybrid electrodes are fully functional in polymer solar cells and polymer light‐emitting diodes, outperforming the conventionally transferred GR electrodes and indium tin oxide electrodes.     

Stochastic Power/Ground Supply Voltage Prediction and Optimization Via Analytical Placement

Increasingly significant power/ground (P/G) supply voltage degradation in nanometer VLSI designs leads to system performance degradation and even malfunction, which requires stochastic analysis and optimization techniques. We represent the supply voltage degradation at a P/G node as a function of the supply currents and the effective resistance of a P/G supply network and propose an efficient stochastic system-level P/G supply voltage prediction method, which computes P/G supply network effective resistances in a random walk process. We further propose to reduce P/G supply voltage degradation via placement of supply current sources, and integrate P/G supply voltage degradation reduction with conventional placement objectives in an analytical placement framework. Our experimental results show that the proposed stochastic P/G supply network prediction method achieves 10x-100x speedup compared with traditional SPICE simulation, and the proposed P/G supply voltage degradation aware placement achieves an average of 20.9% (11.7%) reduction on maximum (average) supply voltage degradation with only 4.3% wirelength increase.     

GA-optimized decoupling capacitors damping the rectangular power-bus' cavity-mode resonances

The genetic algorithm (GA) is suggested to find the decoupling capacitors for suppressing the cavity-mode resonances in the printed circuit board power-bus structure. The optimal positions and circuital values of decoupling capacitors are efficiently determined to selectively mitigate specific resonance peaks. The optimization of the damping is validated with the measurement and develops to multiresonance modes' damping.